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E46 (1999 - 2006) The fourth generation 3 Series (E46 chassis) was introduced in 1999 and set the standard for engineering and performance during it's years of production including being named to Car & Driver's 10 best list every one of those years! ! -- View the E46 Wiki

I noticed a rattling noise in the engine on cold start in am. I sounds like the noise is coming from the front engine. The rattling noise dissipates after the engine warms up. It only happens in cold start then goes away afterwards.

Does anybody experience similar problems? Any advise is appreciated. (02' 325i w/SP)

I seem to be getting terrible noise from my engine as well and I just bought a 2005 325XI in November. It runs fine, but sounds terrible. It is about -5 to -10 average here and we are in February right now. Not sure if that is normal in these weather conditions, but I do not like it.

I noticed a rattling noise in the engine on cold start in am. I sounds like the noise is coming from the front engine. The rattling noise dissipates after the engine warms up. It only happens in cold start then goes away afterwards.

Does anybody experience similar problems? Any advise is appreciated. (02' 325i w/SP)

I am in an opposite situation.. the rattle noise only appears when the car warmed up, and only at a certain rpm about 1000~1200 I am taking it to dealer next tuesday see what the hell going on

I noticed a rattling noise in the engine on cold start in am. I sounds like the noise is coming from the front engine. The rattling noise dissipates after the engine warms up. It only happens in cold start then goes away afterwards.

Does anybody experience similar problems? Any advise is appreciated. (02' 325i w/SP)

What's your oil level in the car? When was the last time you checked it? Could be valve/lifter noise...

I noticed a rattling noise in the engine on cold start in am. I sounds like the noise is coming from the front engine. The rattling noise dissipates after the engine warms up. It only happens in cold start then goes away afterwards.

Does anybody experience similar problems? Any advise is appreciated. (02' 325i w/SP)

I believe its the air pump under the hood (cylinder, black object on RH side of engine bay). Part of emissions equipment, most seem to make a "rattle" noise on cold start up and then disappears after 2 minutes.

I could be wrong but others have found this to be making the noise you are referring to. I forgot if it is called AIR PUMP or AIR INJECTION PUMP or neither...try a search on those.

I noticed a rattling noise in the engine on cold start in am. I sounds like the noise is coming from the front engine. The rattling noise dissipates after the engine warms up. It only happens in cold start then goes away afterwards.

Does anybody experience similar problems? Any advise is appreciated. (02' 325i w/SP)

Mine sounds like the belts squealing (high pitched) but lasts about the same amount of time in the cold. It's not a rattle. Is this the same thing?

No, more than likely it IS your belts. Get some belt spray at your local parts store--this should quite them down or at least you can eliminate that issue. If it is the belts and the spray doesn't work, you need the belt tightened.

I too have an '02 325i with SP and noticed a noise during the first couple minutes of a cold start this week. Sounds like its coming from the fan area behind the radiator. Haven't looked further.

DO NOT USE BELT SPRAY! That stuff is made for the old V belt systems.

You are exactly right to where the noise is coming from.

I called the dealer to make an appointment regarding the noise. It's more like a rattling squealing noise at the same time. The minute I describe the conditon, I was told that it was a normal condition. Most of their loaner cars make the same noise on cold start.

It's strange, it didn't make that noise for the first year we owned car.

This is what my service rep said it most likely was on my car as well.
Simptoms:
It only happens on first cold start. Happens below 45 degrees. lasts about 1-2 minutes. Sound is louder/quieter when A/C is turned on/off.

I had them check it out when I had my regulators replaced, but obviously they couldn't reproduce it due to the fact that it wasn't the first cold start of the day. They want me to bring it back in on a colder day to soak over night. Warrenty is up on the 27th

Mine sounds like the belts squealing (high pitched) but lasts about the same amount of time in the cold. It's not a rattle. Is this the same thing?

I had the exact same symptoms around 60k miles in my 323. It sounded like a belt. When I took it in, it was something with the fan and they replaced it. It didn't make the noise when I arrived, but as I described it the tech seemed to know almost what it was. They had to order the part.

I experienced the exact symptom, and the dealer traced the problem to the belt tensioner.

My car has been experiencing the same problem as well, I meant to take it to be looked at for a few months now but will finallly take it in a week. But from speaking with a BMW tech, he mentioned the belt tensioner as well.

I had the dealer look at it 2 or 3 times and eventually gave up. Either the dealer changed the tension and it came right back, or it was too warm the day they had it and they could not fix it. I have two 3s and a 525i which all do the same thing (same engine in all three) so I am getting a new 3 and hoping the e90 is better.

My car has been experiencing the same problem as well, I meant to take it to be looked at for a few months now but will finallly take it in a week. But from speaking with a BMW tech, he mentioned the belt tensioner as well.

Had the same problem and they put in a new tensioner but after awhile the noise came back.They put in a up dated hydraulic tensioner and the noise never came back no matter what the weather was.
Good luck
vern

Had the same problem and they put in a new tensioner but after awhile the noise came back.They put in a up dated hydraulic tensioner and the noise never came back no matter what the weather was.
Good luck
vern

Hydraulic tensioner? Sounds interesting, do you know what the original one is?

Hydraulic tensioner? Sounds interesting, do you know what the original one is?

I'll mention that to them when I am there.

It's a spring loaded tensioner... there is a Service Bulletin on that.

They thought that was why my car was making the squealing on cold start, so they were about to replace the tensioner when they took a look and discovered I already have the new style hydraulic tensioner. So for me, it's something else...

It's a spring loaded tensioner... there is a Service Bulletin on that.

They thought that was why my car was making the squealing on cold start, so they were about to replace the tensioner when they took a look and discovered I already have the new style hydraulic tensioner. So for me, it's something else...

My is an '03 too, but a early production '03. The suspense holds until next week! Hope they will be able to get it right.